| As pipeline infrastructure systems continue to age and deteriorate, efficient and effective repair or replacement, and maintenance scheduling to reduce the associated significant costs are critical but remain challenging. Pipeline inspection technologies and innovative solutions need to be improved and/or developed in order to provide cost effective solutions to assist the pipeline safety and reliability full decision support system. Moreover, identification and classification of current vintage pipeline inner wall damage precursor are of critical importance. However, there are limited success in sensing and characterizing the small diameters of pipelines with high probability of detection (POD) [3], and the capability of the currently available accelerometers and imaging technologies that can be miniaturized and integrated into smaller size pipes for a fast scan is questionable and needs a systematic assessment. The major drivers of premature failure due to slow crack growth are bending stresses due to tight bend radii, impingement and fittings. Damage is also introduced by pipe squeeze-off during maintenance operations. These conditions identification has been investigated by various nondestructive evaluation (NDE) [2] techniques, such as direct visual/optical methods using CCD cameras, ultrasonic testing, liquid-coupled acoustic measurement (e.g. sonar) and laser based surface inspection approaches including light detection and ranging (LiDAR)[18][19] and laser topography. However, these currently available technologies suffer either from low-sensitivity and resolution for small damage precursors, or complex settings and large system footprint that makes it incapable for plastic pipes with much smaller diameters.;In this thesis three different generations have been designed in order to obtain 3D visualization. The first generation concentrated to scanning the 3 inches pipes with linear defects. Laser source and camera with small view angle have been used to collect the data. There are missing parts in the final 3D image because the angle of the camera is small to capture all the scene. For this reason, the second generation is illustrated to decrease the shadow area that occurs from the view angle of the camera. Another camera with large view angle (fisheye camera) is used with the laser source to obtain full ring without missing parts. The third generation is structured light scanning. A new slide projector with two rings two colors has been designed to capture the scene in order to generate 3D reconstructed image. A pipe with squeezed part is used to do this test by using the structured light scanning. 3D reconstructed image illustrated the squeezed part in the pipe, and this twisted part has a shape of an ellipse instead of a circle. Then, the semi-major and semi-minor axes are calculated to define the eccentricity in order to clarify the frames with squeezed part. Misalignment correction is applied to reduce the camera tilting that occurs from using human hands while doing the scan. |
